Nikolai Ivanovich Lobachevsky (Никола́й Ива́нович Лобаче́вский, 1792–1856) was a Russian mathematician. He became known for his achievements in non-Euclidean geometry.
Nikolai Ivanovich Lobachevsky (Никола́й Ива́нович Лобаче́вский, 1792–1856) was a Russian mathematician. He became known for his achievements in non-Euclidean geometry.